Open-air, air conditioned residential or recreational facility

ABSTRACT

An open-air, air-conditioned residential or recreational facility in a climatically hot environment, said facility comprising: (i) a physical boundary surrounding the area of said facility and elevating to a predetermined height above the ground surface of said facility, wherein said boundary is adapted for reducing the lateral exchange of air between the area inside said boundary and the environment outside of said boundary; and (ii) an electrically-powered cooling system for cooling the ground of said area and the air near the ground surface of said area.

FIELD OF THE INVENTION

The present invention relates to an open-air, air-conditionedresidential or recreational facility for a climatically hot environment.The invention further relates to a method of air-conditioning anopen-air residential or recreational facility in a climatically hotenvironment.

BACKGROUND OF THE INVENTION

In climatically hot places like in tropical or sub-tropicalenvironments, temperatures during day time often exceed 35° and even 40°C. in the shadow. People living under such circumstances suffersignificantly from the heat which frequently leads to health problems.In closed areas like buildings, air-conditioning may be used forreducing the temperature. In residential or recreational areas likeparks, i.e. outdoors, no satisfactory cooling systems have been known.

It is therefore an object of the invention to provide an open-air,air-conditioned facility for a climatically hot environment.

SUMMARY OF THE INVENTION

The present inventions now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the inventions are shown. Indeed, these inventions may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

Open-air, air-conditioned residential or recreational facility in aclimatically hot environment, said facility comprising

-   -   (i) a physical boundary surrounding the area of said facility        and elevating to a predetermined height above the ground surface        of said facility, wherein said boundary is adapted for reducing        the lateral exchange of air between the area inside said        boundary and the environment outside of said boundary; and    -   (ii) a cooling system for cooling the ground of said area and/or        the air near the ground surface of said area.

In one embodiment, said cooling system comprises an air-conditioningrefrigerating unit. Said cooling system may comprise a refrigeratingunit and a coolant fluid. Said refrigerating unit may be capable ofcooling said coolant fluid. Said coolant fluid may flow or circulate onthe ground surface or below the ground surface of said area.

The invention also provides a method for air-conditioning an open-airresidential or recreational facility (in the following briefly:“facility”) in a climatically hot environment, comprising

-   -   providing a physical boundary surrounding the area of said        facility and elevating to a predetermined height above the        ground surface of said facility, wherein said boundary is        adapted for reducing the lateral exchange of air between the        area inside said boundary and the environment outside of said        boundary; and    -   operating an electrically-powered cooling system for cooling the        ground of said area and/or the air near the ground surface of        said area.

Preferred embodiments are defined in the subclaims.

The inventor has surprisingly identified a way of conditioning the airin large, open-air territories like in residential or recreationallocations. Surprisingly, it was found that it is possible to maintain asignificant temperature difference between the outside and the inside ofsaid boundary using a relatively low height of said boundary, since thecooled air stays near the ground and does not give rise to convection.Thus, the inventor has found a way of artificially creating a microclimate of reduced temperature applicable to town construction. Theinvention is of particular use in hot tropical or sub-tropicalenvironments where a reduction of the air temperature even by somedegrees represents a substantial improvement for people suffering froman exceeding heat. The cooling system of the invention cools the groundof the area of said facility and/or the air near the ground. Saidphysical boundary surrounding said area is of sufficient height forreducing lateral exchange of air between the area inside said boundaryand the outside environment of said boundary, thus preserving thecoolness achieved by the cooling system.

Said boundary reduces, preferably prevents, lateral exchange of air atleast near the ground surface of said facility. The height up to whichsaid lateral exchange of air may be reduced or prevented depends on theheight of said physical boundary. The higher said boundary, the higherthe height up to which said lateral exchange can be reduced andprevented. The height up to which coolness may be preserved inside saidfacility thus depends on the height up to which said lateral exchange ofair is reduced or prevented by said physical boundary. Cool air producednear the ground inside said area has a higher density than uncooled air.Therefore, cooled air will stay at the bottom and has little tendency tomix with uncooled air above the cool air as long as wind or agitation isessentially absent. If cooling is continued at a sufficient power, alayer (“sea”) of cool air will form extending over the entire area ofsaid facility. When cooling is continued at a sufficient power, thethickness of the layer of cool air increases. The thickness of the layerof cool air cannot extend beyond the height of said physical boundary.However, the thickness of the cool air layer can be as high as several(e.g. 2 or 3) stories of a building inside said facility.

The cool air inside said facility has a higher density than uncooled airoutside said facility, leading to a higher air pressure at the groundinside said facility compared to outside said facility. Thus, the coolair inside said facility has a strong tendency to spread over a largearea for reducing the thickness of the layer of cool air, whereby thecool air would dissipate and get lost. In this invention, spreading ofcool air is restricted to the area inside said facility by said physicalboundary. Thus, the cool air is kept inside said facility. In oneembodiment, said physical boundary is free of significant openings (i.e.openings of a significant size) that would allow cool air from theinside to be pressed out to the environment. Cool air that is lostthrough openings in said boundary is replaced by uncooled air fromabove, whereby the layer of cooled air inside said facility becomesthinner and may vanish entirely. Said physical boundary should thereforenot have openings that would lead to loss of cool air from the inside tothe outside. On a length (in horizontal direction) of 100 m of thephysical boundary, openings in the physical boundary should, together,not be bigger than 2 m², preferably openings should not (together) bebigger than 3000 cm², more preferably openings should (together) not bebigger than 1000 cm², and most preferably such openings should(together) not be bigger than 500 cm². Loss of cool air through minoropenings may be compensated by the cooling power of said cooling system.It may also be possible to increase the cooling power, if openings arepresent. Significant openings at a certain height of said physicalboundary will lead to an effective height of said physical boundary atthe height of said significant openings. Said facility may of coursehave an occludable opening like an emergency exit or a sluice (lock) forentering or exiting said facility.

Said facility preferably has no access opening for people or vehicles insaid physical boundary. People or vehicles may access the inside of saidfacility e.g. via a tunnel leading from the outside of said facility toan underground level of said facility to the surface of said facilitymay be reached. The access tunnel should have an occludable door foravoiding loss of cool air through said tunnel. Said underground levelmay have facilities like a parking lot for vehicles. Alternatively,people or vehicles may access the inside of said facility via a passingthat bridges said physical boundary. Such a passing may comprise a rampon both sides of said physical boundary, said ramp leading up to the topof said physical boundary. Such a passing is well suited for givingvehicles like cars access to said facility.

Herein, “cool” means colder than in the absence of an operating coolingsystem in said facility. Notably, “cool” means colder than thetemperature (measured in the shadow) of the environment outside saidfacility or above said facility at a height higher than the height ofsaid boundary. If said cooling system cools the ground in said facility,the cooled ground will cool the air above the ground, thereby leading toa layer or sea of cooled air in said facility.

Herein, “inside said facility” or “inside said (physical) boundary”means the area surrounded by said physical boundary including the spaceabove said area up to a height corresponding to the height of saidphysical boundary. “Outside said facility” or “outside said boundary”means the area including the space near said facility excluding theinside of said facility.

The facility of the invention is an open-air facility, i.e. it does nothave a solid roof that would abolish convection of air in the verticaldirection inside said boundary. Of course, parts of said facility may beprovided with means for preventing direct sunlight reaching the ground,like a canvas blind. Air-conditioning herein means a reduction of thetemperature of the air inside compared to the air outside said facilityunder otherwise comparable conditions.

The area of the facility of the invention may be large enough forbuildings like houses and recreational means like parks, lawn, trees,lakes, swimming pools etc. Preferably, the facility of the invention isnot a stadium like a football stadium.

There are many possibilities of powering the electrically poweredcooling system of the invention. The energy required for powering theelectrically powered cooling system of the invention does in general notpose a problem in the climatically hot environments envisioned by theinvention, since abundant solar energy is available, especially duringthe hottest periods of the day, for producing electrical power using asolar power plant.

A solar power plant is preferably located outside said facility forkeeping heat generated by said solar power plant outside said facility.It is preferred to locate the solar light absorption devices of thesolar power plant next to said boundary on the outside of said facility.The solar light absorption devices may be located such that hot airascending from a hot surface of a solar light absorption device mayascend in close proximity to said boundary. At the top of said boundary,said hot air may thus form a cushion of upwardly flowing warm airseparating air inside said facility from air in the environment of saidfacility. Such an air cushion helps to protect the air inside saidfacility from being agitated by wind (see FIG. 5).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 is a schematic view on a facility according to the invention.Numeral 1 indicates buildings. 2 indicates a lawn. 3, 5, and 8 indicatea physical boundary. 4 indicates a lake of water acting as coolant. 6indicates trees, hedges, and shrubs. 7 indicates a street.

FIG. 2 shows a wall as a physical boundary according to the invention.The wall is stabilized by a dam of soil or an earth bank on the outsideof said facility.

FIG. 3 shows a building built on said physical boundary. The buildingforms part of the boundary of the invention. The refrigerated groundinside the facility extends into the ground floor of said building foradditionally conditioning the air temperature inside said house.

FIG. 4 shows an assembly of seven facilities according to the invention.The seven facilities are designated M1, M2, M3, M4, M5, M6, and M7,respectively. M1 may have a size of 10,000 m². M2 and M3 may have a sizeof 20,000 m², and the remaining facilities may have a size of 30,000 m².Straight lines indicate physical boundaries. Adjacent facilities share acommon physical boundary. The assembly of several facilities sharingcommon boundaries has the advantage that wind has a less detrimentaleffect on the cool air layers inside the facilities compared to onelarge facility having an area equal to the sum of the areas of the smallfacilities M1 to M7. Numeral 20 indicates air-conditioning devices offacility M2. Numeral 22 indicates three air-conditioning devices offacility M6. Air-conditioning devices of the other facilities areindicated. The air-conditioning devices are located at said physicalboundaries. Heat produced by said devices is conveyed to the outside ofsaid facilities. Central facility M1 may have a cooling system that iscapable of conveying heat generated by said cooling system to theoutside of the assembly of facilities. This may e.g. be achieved byconveying the heat to the space above said facility and conveying thecool air produced by the air-conditioning unit to the ground of centralfacility M1. An air-conditioning unit of central facility M1 may e.g. bemounted at a building in facility M1 at a height higher than the heightof said boundary. Generated heat may then be released to the outside ofsaid facility and cool air may be conveyed down into the sea of coolair. Cool air lost from an air-conditioned building in a facility mayfeed the sea of cool air of said facility, thereby preventing loss ofcool air from such an air-conditioned building.

FIG. 5 shows a cross-section through an element of the physical boundaryplaced on the ground (hatched). The physical boundary is capable ofcreating a cushion of hot air III capable of protecting the sea of coolair I and the air II above said sea of air I from wind coming from theright hand side. Roman capital numerals indicate various air layers thatdiffer in air flow conditions and/or temperature. Dashed lines indicatedfrontiers between differing air layers. Arrows indicated the directionof air flow or wind. The inside of said facility is on the left side ofthe physical boundary. 32 indicates the right hand side of a hollowboundary element, made e.g. of steel, glass, or steel-glassconstruction. 34 indicates the left hand side of the hollow boundaryelement. 36 indicates the hollow inside of the boundary element. 40indicates a transparent plate made of glass. 38 and 42 indicate openingsto the inside of the hollow boundary element. 46 indicates an opening atthe top of said boundary element. 44 indicates a dark or black layerunder the glass plate 40. Back layer 14 may be a sun collector forgenerating electrical energy for powering said cooling system. Lightfrom the sun will pass through glass plate 40 and hit on black layer 44.Black layer 44 absorbs sun light, whereby it heats up. The hot layer 44heats up the air above said layer, which will ascend. Ascending hot aircreates an air flow upwards in said hollow boundary element, wherebysaid boundary element functions like a chimney. Ascending air in theboundary element exits the boundary element at opening 16. Air may entersaid boundary element at openings 38 and 42. The hot air ascending insaid boundary element and being accelerated therein creates a cushion offlowing warm air indicated at III. Said cushion III directs wind comingfrom the left hand side upwards as indicated at IV. Thus, air layers Iand II inside said facility are at least partially protected from windby air cushion III.

As indicated by the location of the dashed line between air layer I andII, the thickness of the sea of cool air I can be less than the heightof said boundary. The thickness of the sea of cool air I is at most ashigh as the height of said boundary.

DETAILED DESCRIPTION OF THE INVENTION

The present inventions now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the inventions are shown. Indeed, these inventions may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

The facility of the invention may be large enough to include buildingslike residential buildings, hotels or recreational facilities likeswimming-pools, lawns, sport facilities etc. The facility may include anentire (urban) settlement. The area of said facility inside saidphysical boundary may have a size of at least 100 m², preferably atleast 500 m², more preferably at least 2000 m², and most preferably atleast 10,000 m². The area may however be even larger, e.g. 1 km².Preferred sizes are between 10,000 m² and 1 km², preferably 10,000 to50,000 m². Instead of constructing one large facility, it is preferredto construct an assembly of several adjacent smaller facilities forreducing the risk of losing cooled air by wind. In such an assembly offacilities, adjacent facilities preferably share a common physicalboundary. The number of facilities that may be arranged to form anassembly of facilities is not limited and my e.g. be 2 to 10,preferably, 4 to 8.

There are no limits regarding the shape of the facility of theinvention. The shape may for example be round, rectangular,cross-shaped, or irregular. The shape of the facility is determined bythe shape of said physical boundary. The buildings inside the facilitymay be arranged in any form of conventional settlements. Buildingsinside said facility may be integrated into said boundary, e.g. suchthat the building forms part of said boundary.

The cooling efficiency (cooling power) to be used for the cooling systemof the invention depends, apart from its power, from the level oflateral air exchange between the area inside said boundary and theenvironment outside said boundary. The exchange of air e.g. in case ofwind, in turn, depends inter alia on the height of said boundary and thesize of the area inside said facility. The size of said area, the heightof said boundary, and said cooling system should be mutually adjusted toeach other for allowing to achieve a desired air-conditioning effect.Preferably, they are mutually adjusted such that the air temperaturenear the surface of said area is at least 2°, preferably at least 5°,more preferably at least 7° C. lower than the temperature in the outsideenvironment during day time. (Temperatures and temperature differencesare measured in the shadow under otherwise comparable conditions likedistance from the ground.) Said cooling system should be capable ofcooling the air near the ground surface of the area inside said facilityto a temperature between 18° and 35° C., preferably between 25° and 35°C., more preferably to a temperature between 25° and 30° C.

Obviously, the lateral exchange of air between the area inside saidboundary and the environment outside said boundary depends to a largeextent on the presence or absence of wind. The above-mentionedtemperatures and temperature differences relate to a situation wherewind is essentially absent, preferably entirely absent. In the presenceof wind, the air-conditioning effect of the facility of the inventionwill be worse than in its absence. However, in the presence of wind,heat is perceived as less stressing by humans. On the other hand, if awind abates, the cooling effect of the facility of the invention willimmediately return.

The height of said physical boundary should be the higher, the largerthe size of said facility. Said boundary may have a height of at least 2m, preferably at least 3 m, more preferably at least 4 m. For largesizes of said facility, the height may be even higher, e.g. between 5and 20 m. Said physical boundary does not have to have the same heightthroughout. It may be higher at places where a stronger lateral airexchange is expected from the specific location or wind conditions atthe specific site where said facility is constructed.

Said physical boundary may be made of any material capable of reducing,preferably preventing, lateral air exchange across said boundary. Saidphysical boundary does not have to be air impermeable provided it iscapable or reducing said air exchange. It may comprise a woven (e.g.canvas) or a non-woven fabric. Further, it may be formed of a denselyplanted plants like trees and bushes. Preferably, said boundary is airimpermeable. In an important embodiment, said physical boundary is awall. Said boundary may further be made of at least one materialselected from the group consisting of: concrete, brickwork, wood, glass,metal, and plastic. Houses of said facility may be part of said physicalboundary, whereby the walls of said house form said boundary. If saidboundary is a wall of a height of at least several meters, the wall maybe strengthened by a dam or soil or by other strengthening means. Saidboundary may also be an earth wall. Said boundary may be made ofdifferent materials along its circumference. Natural conditions likerocks may be included in said boundary at a portion of said boundary. Ina further embodiment, the physical boundary may be made of differentmaterials in different heights. For example, the physical boundary maycomprise a dam at the bottom and a wall constructed on said dam. Ifrequired, a woven fabric may be tentered between masts on the top ofsaid wall, e.g. for reducing a negative effect of wind on the air insidesaid facility.

Moreover, the ground surface of the area of said facility may be locatedlike a valley below the surface of the outside environment, therebyreducing lateral exchange of air between the area inside said boundaryand the environment of said boundary.

Said physical boundary surrounds the inside area of said facility.Preferably, said physical boundary surrounds the area of said facilitycompletely. However, means for providing access to the inside of saidfacility are preferably provided. Such a means may be an opening.Preferably, the opening can be closed by a door for minimizing lateralair exchange between inside and outside. In another embodiment, theremay be a way like a street going over the boundary, e.g. using a bridge.Further, access to the inside of said facility may be provided by atunnel underneath said boundary.

In one embodiment, cool water as a coolant may be available e.g. form acool fountain and electrical power is used for distributing said coolantto desired locations in said facility e.g. using an electrical pump.Said coolant may e.g. be pumped up to a certain level above the groundand then allowed to flow down (e.g. in drops) at various places therebycooling the ground and the air inside said facility. In a preferredembodiment, said cooling system is an electrically-powered coolingsystem in that electricity is used for cooling down a coolant fluid(e.g. in a refrigerator using an electrical pump for making use of theJoule-Thomson effect).

The cooling system of the invention may be an electrically-poweredrefrigerating unit. Refrigerating units that may be used for theinvention are known in refrigerating technology. Examples areconventional air-conditioning devices. The power of the refrigeratingunit should be adjusted to the size of the facility to beair-conditioned. Several refrigerating units (like air-conditioningdevices) may be run in parallel in said facility. The required numberand power of refrigerating units can be determined by a man skilled inthe art of heating engineering depending on the size of the facility,the temperature difference to be achieved, and other circumstances. Heatgenerated by the refrigerating unit (e.g. upon cooling of the coolantfluid) has to be conveyed to the outside of said facility. Saidrefrigerating unit(s) are preferably located close to said physicalboundary such that the heat generated by the refrigerating unit caneasily be conveyed to the outside environment of said facility (e.g. tothe outer side of said boundary or to the space above said facility).Most preferably, said refrigerating unit(s) may be integrated into saidboundary. In general, said cooling system comprises many refrigeratingunits for providing sufficient cooling power. These refrigerating unitsmay be arranged along said boundary, e.g. equally spaced. The cooled airproduced by said refrigerating units is released to the inside of saidfacility. The cooled air may be released at the ground surface of thearea of said facility. The cooled air may also be released at apredetermined height above the ground surface of said facility, e.g at aheight of 1 or 2 meters. In any case, the cooled air should be releasedat a height lower than the height of said physical boundary.

Alternatively or additionally, said cooling system may comprise arefrigerating unit and a coolant fluid cooled by said unit, whereby saidcoolant fluid flows or circulates on the ground surface or below theground surface of said area. The cooling effect of said coolant may bebased on the take up of heat by said coolant from the air or the groundinside said facility. Alternatively or additionally, the cooling effectmay be based on a phase transition of the coolant e.g. evaporation ofwater as a coolant.

Said cooling system may comprise a coolant fluid that is cooled by saidrefrigerating unit(s). The type of coolant fluid depends on the coolingprinciple employed and may be any conventional coolant like a gas (e.g.natural or artificial air, carbon dioxide, nitrogen, propane, butane,fluorinated hydrocarbons etc.) or a liquid. The most preferred liquidcoolant fluid is water. After having cooled the coolant fluid, thecoolant fluid, notably water, may be allowed to flow on the surface ofthe area inside said facility. Water as a coolant fluid may form lakesor little rivers cooling the ground inside said facility and the airnear the ground inside said facility. Evaporation cooling by waterevaporation may contribute to the cooling effect. It is preferred toarrange the course of the coolant fluid such that it may circulate backto the refrigerating unit to be cooled again.

The cooling system may comprise a duct system like a pipe system forsaid coolant fluid. The duct system is preferably located below thesurface of the area of said facility. Said duct system allowscirculation of said coolant fluid. The duct system and the refrigeratingunit may form a closed system for the coolant fluid, allowingcirculation of said coolant fluid. The duct system should be installedjust below the surface of the ground for allowing efficient thermalconduction between the duct system and the surface. Alternatively, theduct system may be an open system that releases cooled coolant fluid atselected locations in said facility. In the latter case, the coolantfluid may be air, nitrogen, or carbon dioxide, preferably air. If saidduct system is a pipe system, the pipes are preferably made of metal.

The cooling system of the invention may make use of the Joule-Thomsoneffect for cooling the coolant fluid. The coolant fluid cooled using theJoule-Thomson effect may be used directly for cooling said facilitypreferably in a closed system. Alternatively, the coolant fluid cooledusing the Joule-Thomson effect is a primary coolant that cools asecondary coolant. Primary coolant fluids having a favourableJoule-Thomson effect for use in refrigerators are known in the art. Thesecondary coolant (e.g. water, air, etc.) may then be used (indirectly)for cooling said facility.

Said refrigerating unit should be capable of cooling said coolant fluidto a temperature between 0° and 30° C., preferably to a temperaturebetween 5° and 25° C.

In the cooling system of the invention, various refrigerating units maybe combined for achieving the desired cooling effect. For example, thecooling system may comprise air-conditioning refrigerating units and arefrigerating unit cooling a coolant fluid flowing or circulating on theground surface or below the ground surface of said area. Further, thecooling system may comprise a device that produces and spreads aqueousfog, whereby heat is consumed upon transition of the fog to the gasphase.

Said refrigerating unit is most preferably an electrical refrigeratingunit powered by a solar power plant, since solar energy is abundant inclimatically hot environments, notably in sub-tropical environments likeArab countries on the Arabian peninsula.

BEST MODE OF THE INVENTION

Open-air, air-conditioned residential or recreational facility in aclimatically hot environment, said facility comprising

-   -   (i) a physical boundary surrounding the area of said facility        and elevating to a predetermined height above the ground surface        of said facility, wherein said boundary is adapted for reducing        the lateral exchange of air between the inside of said facility        (inside said boundary) and the environment outside of said        boundary; and    -   (ii) an electrically-powered air-conditioning refrigerating unit        for cooling the air near the ground surface of said area;

wherein said physical boundary surrounds said area completely withoutleaving an opening in said physical boundary that would allowsignificant loss of cooled air from said area to the outside of saidarea.

The article “a” and “an” are used herein to refer to one or more thanone (i.e., to at least one) of the grammatical object of the article. Byway of example, “an element” means one or more element.

All publications and patent applications mentioned in the specificationare indicative of the level of those skilled in the art to which thisinvention pertains. All publications and patent applications are hereinincorporated by reference to the same extent as if each individualpublication or patent application was specifically and individuallyindicated to be incorporated by reference.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the appended claims.

1. An open-air, air-conditioned residential or recreational facility ina climatically hot environment, said facility comprising: (i) a physicalboundary surrounding the area of said facility and elevating to apredetermined height above the ground surface of said facility, whereinsaid boundary is adapted for reducing the lateral exchange of airbetween the inside of said boundary and the environment outside of saidboundary; and (ii) an electrically-powered cooling system for coolingthe ground of said area and/or the air near the ground surface of saidarea.
 2. The facility according to claim 1, wherein said physicalboundary surrounds said area without leaving an opening in said physicalboundary that would allow significant loss of cooled air from said areato the outside of said area.
 3. The facility according to claim 1,wherein said boundary surrounds said area completely and preventslateral exchange of air near the ground surface of said facility.
 4. Thefacility according to claim 1, wherein said cooling system comprises anair-conditioning refrigerating unit.
 5. The facility according to claim1, wherein said cooling system comprises a refrigerating unit and acoolant fluid, said refrigerating unit being capable of cooling saidcoolant fluid.
 6. The facility according to claim 1, wherein saidcooling system is powered by a solar power plant.
 7. The facilityaccording to claim 1, wherein said physical boundary is or comprises awall of a height of at least 2 m.
 8. The facility according to claim 1,wherein said physical boundary is or comprises a wall of a height of atleast 3 m.
 9. The facility according to claim 1, wherein said physicalboundary is or comprises a wall of a height of at least 4 m.
 10. Thefacility according to claim 1, wherein said physical boundary is made ofat least one material selected from the group consisting of: soil,concrete, brickwork, wood, glass, metal, plastic, and a woven ornon-woven fabric tentered between masts.
 11. The facility according toclaim 1, wherein the size of said area, the height of said boundary, andsaid cooling system are mutually adjusted such that the air temperaturenear the surface of said area is at least 2° C. lower than thetemperature in the environment during day time as measured in theshadow.
 12. The facility according to claim 1, wherein the size of saidarea, the height of said boundary, and said cooling system are mutuallyadjusted such that the air temperature near the surface of said area isat least 5° C. lower than the temperature in the environment during daytime as measured in the shadow.
 13. The facility according to claim 1,wherein the size of said area, the height of said boundary, and saidcooling system are mutually adjusted such that the air temperature nearthe surface of said area is at least 7° C. lower than the temperature inthe environment during day time as measured in the shadow.
 14. Thefacility according to claim 1, wherein said facility comprises a dark orblack area on the outside of said facility at said physical boundary,said dark or black area being capable of absorbing sun light for heatingup the air above said dark or black area and for producing a flow ofwarm air ascending outside said boundary, said flow of ascending warmair forming a cushion of flowing warm air at the top end of saidboundary.
 15. The facility according to claim 1, wherein the area ofsaid facility inside said boundary has a size of at least 500 m². 16.The facility according to claim 1, wherein the area of said facilityinside said boundary has a size of at least 2000 m².
 17. The facilityaccording to claim 1, wherein the area of said facility inside saidboundary has a size of at least 10,000 m².
 18. An open-air,air-conditioned residential or recreational facility in a climaticallyhot environment, said facility comprising: (i) a physical boundarysurrounding the area of said facility and elevating to a predeterminedheight above the ground surface of said facility, wherein said boundaryis adapted for reducing the lateral exchange of air between the insideof said facility and the environment outside of said boundary; and (ii)an electrically-powered air-conditioning refrigerating unit for coolingthe air near the ground surface of said area; wherein said physicalboundary surrounds said area completely without leaving an opening insaid physical boundary that would allow significant loss of cooled airfrom said area to the outside of said area.
 19. A method ofair-conditioning an open-air residential or recreational facility in aclimatically hot environment, comprising providing: (i) a physicalboundary surrounding the area of said facility and elevating to apredetermined height above the ground surface of said facility, whereinsaid boundary is adapted for reducing the lateral exchange of airbetween the inside of said boundary and the environment outside of saidboundary; and (ii) an electrically-powered cooling system for coolingthe ground of said area and the air near the ground surface of saidarea.